In an effort to simplify the dual core approach of the, the 3rd Generation Partnership Project (3GPP) has recommended a new network scheme it terms “Long Term Evolution” (LTE). In an LTE network, all communications are carried over an IP channel from user equipment (UE) to an all-IP core called the Evolved Packet Core (EPC). The EPC then provides gateway access to other networks while ensuring an acceptable quality of experience (QoE) and charging a subscriber for their particular network activity
The 3GPP generally describes the components of the EPC and their interactions with each other in a number of technical specifications. Specifically, 3GPP TS 29.212, 3GPP TS 29.213, 3GPP TS 29.214, and 3GPP TS 29.215 describe the Policy and Charging Rules Function (PCRF), Policy and Charging Enforcement Function (PCEF), Bearer Binding and Event Reporting Function (BBERF) of the EPC, and Policy and Charging Control (PCC) over S9 Reference Point. These specifications further provide some guidance as to how these elements interact in order to provide reliable data services and charge subscribers for use thereof.
A communications network of a network provider usually has a limited geographical range where it can provide communications services. Network subscribers usually subscribe to a single network. When a network subscriber is outside of the geographical range of the subscribed network, another network provider may provide network service to the subscriber, who is then considered a roaming subscriber in this visited network. The subscriber's home network and the visited network must negotiate in order to provide network service to the subscriber and correctly apportion the costs of the service. LTE networks use the S9 reference point to communicate between a visited PCRF (V-PCRF) node and a home PCRF (H_PCRF) node. The use of the S9 reference point can lead to some functional limitations in certain scenarios. Therefore, improvements to handling of Rx messages or IPCAN session messages without subscription IDs at a home-PCRF for roaming sessions would be highly desirable.